This invention is directed to a utility knife and, in particular, to a hand held utility knife with a cutting blade that can be stored in a handle and extended from the handle to any desirable length from the handle to a fully extended position.
The utility knife is commonly used for various cutting needs around the house and by a craftsman to serve the cutting needs associated with a job or profession. For example, wrapping and shipping materials and goods in containers, as well as opening containers, frequently require the use of a utility knife to make the job much easier to accomplish. The length of the cutting blade extending from the handle is critical for not cutting to a depth that would damage goods beyond the material that needs to be cut. The goods that should not be damaged can be at any length relative to the end of the knife handle from which the blade extends. The use of a utility knife is further improved by the general shape of the handle. The shape of the handle relative to the cutting blade provides a gripping surface for better alignment of the blade with respect to the material being cut.
A typical utility knifes of the general type being described herein are disclosed in U.S. Pat. Nos. 4,242,795; 5,960,050; and 6,321,454 B1. The knife handle of ""795 discloses a handle that is depressed for manipulating and latching a blade relative to a handle opening. A thumb button allows a latching tab of a resilient finger extending from a blade carrier to engage a notch in the handle depression to fix the extension of the blade from a front end of the handle. A series of four notches is provided to allow four positions of the blade relative to the handle opening. The disclosure of ""050 provides a utility knife having a curvilinear slot in the side of the handle that guides a button to advance the blade in a rectilinear track to extend from the handle. The button is part of a mechanism having a spigot on an end that fits into a hole in the blade for extending the blade from the front end of the handle. The mechanism is guided by internal ribs and a detent in the mechanism engages detent recesses in the handle for positioning the blade. The detent recesses are to provide for a xe2x80x9csnap-offxe2x80x9d type blade so the recesses correspond to the score lines in the blade. If a trapezoidal blade is used the blade must have one or more holes. Once again the number of positions that the blade extends from the housing is limited. The utility knife of ""545 discloses guide cheeks of the handle housing to ensure the knife cuts in a uniform angular relationship relative to an adjacent planar surface to insure that the blade cuts material at a uniform and preselected angle. This utility knife has an elongated and curvilinear handle so that gripping the handle at different locations adjusts the angle of the hand relative to the blade. The utility knife of ""545 also provides a blade at both ends for providing alternate angular relationships of the blade relative to the hand. The blades of this patent are not adjustable in the length from the handles.
The need remains to have a utility knife that can be adjusted so that the blade extends from the handle at any desired cutting length from the front end of the handle. This cutting length adjustment is necessary to cut only the material to be separated and not damage any of the material not being cut by the blade. A further need exists to be able to adjust the relationship between the hand held body portion of the utility knife and the blade retainer portion for better gripping to control the depth of a cut.
Accordingly, an object of the present invention is to provide a utility knife where the length of the blade extending from the front end of the housing can be easily adjusted by hand to any value between fully extended and fully retracted.
Another object of the present invention is to provide alternate structural means for extending and retracting the cutting blade of the utility knife to provide a variable and stable cutting length for the blade extension from the blade opening of the handle.
Still another object of the present invention is to provide an elongated handle body that is modified to change the orientation between the cutting blade assembly and the gripping surface portion of the handle and to provide blade storage in the handle.
The above objectives are accomplished according to the present invention by providing a blade assembly and a blade deployment device supported in an internal cavity within a knife handle. In particular, the blade can be extended any desired distance from the front face of the handle between the full deployed position and the fully retracted position. No additional structure or locking devices are generally required to retain and hold the blade in a predetermined position from a handle opening when it has been deployed by the blade deployment device. An alternate locking collar can be provided to prevent accidental changes in the blade deployment length while the material is being cut.
A hand held utility knife or RollaBlade of this invention comprises a knife handle having first and second handle halves, an internal cavity and a blade opening. The handle halves are held together by a connector. A blade assembly is provided having a blade retainer and a cutting blade. The blade retainer is slidably mounted within said internal cavity of said knife handle to support the cutting blade to extend from the blade opening. A blade deployment device is mounted in the internal cavity of the handle to be accessible from the exterior of the handle for moving the blade retainer to extend the blade from the blade opening any desired distance from a fully extended position to fully retracted. The cutting blade is held and safely used at any desired intermediate position between fully extended to fully retracted.
In another aspect of the present invention, a utility knife or RollaBlade system is provided for use with hand held utility knifes. The utility knife system comprises a knife system handle having an internal cavity with first and second support ribs and a blade opening at a front end. A cutting blade is carried by a blade retainer within said internal cavity. The blade retainer is slidably supported and guided by the first support ribs. A deployment rod is appropriately attached to the blade retainer for displacing the blade retainer so that the cutting blade extends from the blade opening. A deployment wheel associated with the deployment rod is rotated to displace the deployment rod. The deployment rod and wheel are supported by the second support ribs and the cutting blade is extended and held relative to the blade opening at any desired distance from fully extended to fully retracted.